I'm a new home brewer. Since Christmas I've brewed 5 beers, all of which have been drinkable. The first I didn't have a hydrometer, the second I accidentally put in twice as much carapils as I was supposed to, but the last three have all given me the same anomaly in that og and fg are much lower than stated in the recipe. I can understand og being lower, and am aware of causes of mash inefficiency, some of which I intend to try and mitigate in future brews. What I don't understand is why the og and fg are off by the same amount.
For example my last brew is a Belgian strong golden ale. OG in the recipe was 1.070, and fg was 1.012. my gravities were 1.060 and 1.003. I would expect, if the amount of fermentables was in proportion, that an OG of 1.060 would give a FG more like 1.010. If for some reason the amount of fermentables was not in proportion (i.e the mash resulted in a lower OG of mostly fermentable sugars) I would expect a watery tasting beer, which they're not.
Has anyone experienced anything similar or have any ideas what is happening?
I've used two different hydrometers and have tried to degass samples post fermentation so I don't think these are factors. I'm doing a single step infusion mash in a cooler, which sits at 65c for an hour and maybe loses 1c during that time, followed by 2x batch sparges involving a good stir and 10 mins sitting in ~65c water, then vorlaufing again before running off.